dslinux/linux-2.6.x/drivers/mmc scsd_c.c scsd_s.S

Amadeus amadeus at iksw-muees.de
Mon Aug 28 15:34:49 CEST 2006


Stefan,

On Monday 28 August 2006 14:10, Stefan Sperling wrote:
> If assembly is really necessary, maybe it is possible to write
> small wrappers in assembly that clean up the stack before and after
> C function calls?

Hm. This might be possible, and might be worth trying, because CF 
drivers (for example) have a very simple interface which is easy served 
in C. I will think about it!

> However, I'd much rather have maintanable code that has
> overhead than unmaintanable code without overhead.

I would not call assembler code "unmaintainable". ARM assembler is 
pretty simple, and I am used to comment more than the average linux 
habbit.

> As for the speed optimisation issue - I don't know if it is
> reasonable to optimise things at all costs. Again, I'd prefer
> working, maintainable code to "crazy-speedy-fully-optimised-but-
> few-can-understand-it" code.

Writing assembler is not "at all costs". No, Sir!

And a good commented assembler function is more readable as some of the 
"low-level-C" functions I have seen in the linux kernel which try to 
modify stacks, registers and so on from C.

regards
Amadeus
-- 
We're back to the times when men were men 
and wrote their own device drivers.

(Linus Torvalds)



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